Rubber bumper



FIG. 1 is a front view of a rubber bumper showing my design;

FIG. 2 is a right side view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a perspective view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines shown in FIG. 6 are for the purpose of illustrating portions of the rubber bumper and form no part of the claimed design. 

CLAIM The ornamental design for the rubber bumper, as shown and described. 